I just wanted to report that I finally got a chance to do some gaming on this thing.
Its input lag is *excellent*. At 1080p@120Hz it has less input lag than the seiki SE50UY04/SE39UY04 does at the same resolution/refresh rate. I would say its input lag is about on par when the seiki's are at 720p@240Hz. I am *extremely* sensitive to input lag and I had absolutely no issues playing quake on this thing.
If the 60Hz thing gets fixed this will be an excellent display for games. Very good input lag @ 4k30Hz too (compared to the seiki).
I meant to do some CRT testing (Linux should be more sync'd on the displays than windows) and try to get some real input lag numbers. I borrowed my dad's nikon D80 for this but it died after a single picture so I borrowed his newer nikon and I plan to re-do this test to get some rough input lag numbers or atleast compare them (seiki/vizio) with a CRT.
How's motion clarity compared to the Seiki, and how does its motion processing affect input lag?